Mailing List flyrotary@lancaironline.net Message #58872
From: William Wilson <fluffysheap@gmail.com>
Subject: Re: [FlyRotary] Re: Check Temps on Climbout was e: [FlyRotary]Turboquestion.
Date: Fri, 24 Aug 2012 11:55:02 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
All turbo rotaries should have intercoolers (whether in the air or on the ground).  The purpose of the intercooler is to remove the heat added by the turbo.  As a result they are actually more necessary at high altitude than low because the turbo is working harder.  At 18,000 feet, a turbo boosting just to sea level pressure is working harder than a turbo at sea level boosting 10 PSI, and the air coming out of it will be the same temperature, or hotter.

On Thu, Aug 23, 2012 at 4:45 PM, <hoursaway1@comcast.net> wrote:
Hay Chris,  I'm not turbo savy, but do you realy need an intercooler,,,,,,,at altitude,,,,,, the air is pretty cold already, the racers on the ground need them because the air near the ground is hot, not at 6000+++ feet.  just a thought & will be watching, a turbo instead of a muffler I'm thinking may be a better choice.  David R. Cook  RV6A  Rotary Lansing MI.


From: "Chris Barber" <cbarber@texasattorney.net>

To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Wednesday, August 22, 2012 9:49:50 PM
Subject: [FlyRotary] Re: Check Temps on Climbout was e: [FlyRotary]Turboquestion.


Yes. That is correct. The 3lb spring limits boost it is the lowest I have as I wanted to start low. 
I checked my intercooler and it is flowing well. No obstruction or leak I could find. It may be the location of the blow of valve. I will remove it and see if I get good boost



Sent from my iPhone 4

On Aug 22, 2012, at 6:30 PM, "CozyGirrrl@aol.com" <CozyGirrrl@aol.com> wrote:

Andrew, I believe the 3 lb spring he is talking about is the wastegate spring, this limits boost, the 3 lb one is the lowest boost available, as the springs get stronger the more exhaust is forced through the turbo.
Chris?
 
Chrissi & Randi

www.CozyGirrrl.com
ClickBonds 10/$7.50
CG Products, Custom Aircraft Hardware
Chairwomen, Sun-N-Fun Engine Workshop
 
In a message dated 8/22/2012 6:08:30 P.M. Central Daylight Time, andrew@martinag.com.au writes:
Chris

if your blow off valve is before the intercooler, it may just be opening too soon with that 3lb spring and allowing all your air to vent, then the engine would act as NA but with the intercooler as a added restriction. try a heavier spring.

Andrew

On Thu, Aug 23, 2012 at 6:53 AM, Chris Barber <cbarber@texasattorney.net> wrote:
Thanks Ed. I am pleased you verified my concern after my cooling skyrocketing yesterday when I went to full power.

Trying to determine where the restriction is now.

You are the best.

Sent from my iPhone 4

On Aug 22, 2012, at 4:48 PM, "Ed Anderson" <eanderson@carolina.rr.com> wrote:

> Chris, One thing to be checking on your next take off is your coolant/oil temps.  As you know take-off is the worst combination of low cooling air mass flow and max engine temperature due to WOT.
>
> You would be surprised how quickly (with the additional power you now have) you will exceed your cooling limits if not careful.  So I would be certain to check the temps at a frequent rate on your next take-off until you know how the system is going to react - hate to see you cook your engine during your first real Turbo climb out.
>
> I find for my Rv-6A that I needed to get to 120 mph IAS as quick as possible to get on the good side of the cooling curve.  So that generally meant take off - get safely above surround obstructions, then level off/reduce climb until airspeed hit 120.  Then I could resume climb with cooling gradually bring the temps down as altitude and airflow increased.  Your sweet spot airspeed would undoubtedly be different given different platform and cooling set up.
>
> Ed
>
> --------------------------------------------------
> From: "Chris Barber" <cbarber@texasattorney.net>
> Sent: Monday, August 20, 2012 9:17 PM
> To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
> Subject: [FlyRotary] Turbo question.
>
>> As I have mentioned I have had what I think are incongruent readings regarding my manifold pressure (mp)and engine rpm. It seems I am getting quite low mp as I add power to higher rpm.
>>
>> I am not well versed in this area but my thought is that as I add power, even with slight boost (currently using a 3 lb spring in my wastegate) eventually my mp should raise a bit more.
>>
>> Today I did some static test. I recorded engine RPM with the  turbo hooked up and recorded the mp at 1000 rpm increments. Then I removed the turbo plumbing from my intake and recorded the same info My results currently confuse me.
>>
>> With the turbo hooked up I am getting
>>
>> RPM.   MP inches
>> 2000 - 14.0
>> 3000 - 15.5
>> 4000 - 19.3
>> 5000 - 21.6
>> 5700 - 24.5 (topped out)
>>
>> With the turbo removed.
>>
>> 2000 - 15.8
>> 3000 - 15.3
>> 4000 - 19.7
>> 5000 - 24.8
>> 5833 - 29.8
>>
>> Is this indicative of restriction in my plumbing? Perhaps in the inter cooler? A dirty air filter? A bad pop off valve or a leak not allowing the air pressure getting to the intake. Or????
>>
>> I am uncertain what other permitters I need to check and provide. I am just starting my diagnosis in my Phase One testing. I only have 1.6 hours in the air so far. I value ya'll's direction and input.
>>
>> Heck, perhaps this is working properly but it just doesn't seem right/comfortable.
>>
>> Thanks folks.
>>
>> Chris Barber
>> Houston
>> Velocity SE
>> Rotary 13b turbo (?) :-)
>>
>>
>>
>> Sent from my iPhone 4
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Regards

Andrew Martin
Martin Ag
275 Newmarracarra Rd
Moonyoonooka WA 6532

0427477144
08 99241145
andrew@martinag.com.au

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